Cassava (Manihot esculenta Crantz) is a widely-grown staple food in the tropical and subtropical regions of Africa, Asia, and Latin America. In this brief we examine the environmental constraints to, and impacts of, smallholder cassava production systems in Sub-Saharan Africa (SSA) and South Asia (SA), noting where the analysis applies to only one of these regions. We highlight crop-environment interactions at three stages of the cassava value chain: pre-production (e.g., land clearing), production (e.g., soil, water, and input use), and post-production (e.g., crop storage). At each stage we emphasize environmental constraints on production (poor soil quality, water scarcity, crop pests, etc.) and also environmental impacts of crop production (e.g., soil erosion, water depletion and pesticide contamination). We then highlight good practices for overcoming environmental constraints and minimizing environmental impacts in smallholder cassava production systems. Evidence on environmental issues in smallholder cassava production is relatively thin, and unevenly distributed across regions. The literature on cassava in South Asian smallholder systems is limited, reflecting a crop of secondary importance (though it is widely found elsewhere in Asia such as South East Asia), in comparison to cassava in much of SSA. The majority of the research summarized in this brief is from SSA. The last row of Table 1 summarizes good practices currently identified in the literature. However, the appropriate strategy in a given situation will vary widely based on contextual factors, such as local environmental conditions, market access, cultural preferences, production practices and the policy environment.

This overview introduces a series of EPAR briefs in the Agriculture-Environment Series that examine crop-environment interactions for a range of crops in smallholder food production systems in Sub-Saharan Africa (SSA) and South Asia (SA). The briefs cover the following important food crops in those regions; rice (#208), maize (#218), sorghum/millets (#213), sweet potato/yam (#225), and cassava (#228).

Drawing on the academic literature and the field expertise of crop scientists, these briefs highlight crop-environment interactions at three stages of the crop value chain: pre-production (e.g., land clearing and tilling), production (such as water, nutrient and other input use), and post-production (e.g., waste disposal and crop storage). At each stage we emphasize environmental constraints on crop yields (including poor soils, water scarcity, crop pests) and impacts of crop production on the environment (such as soil erosion, water depletion and pest resistance). We then highlight best practices from the literature and from expert experience for minimizing negative environmental impacts in smallholder crop production systems.

This overview (along with the accompanying detailed crop briefs) seeks to provide a framework for stimulating across-crop discussions and informed debates on the full range of crop-environment interactions in agricultural development initiatives.

This annotated bibliography addresses agricultural transformation and mechanization, dietary diversification and energy needs, and conservation tillage. Each citation is accompanied by an annotation briefly describing the findings and key takeaways.

This literature review provides information on the dynamics of the maize market and maize prices in Zambia. We address four key topics: average production costs and breakeven prices for maize farmers in Zambia, main drivers of volatility of maize production volumes, key factors driving the differences between Zambian and global maize prices, and policies that may have contributed to increased farmer productivity.

Smallholder farmers in Africa are largely located in poor rural areas, are often geographically dispersed, and have limited access to road and communication infrastructure, thus raising the cost of market participation. This is especially true for farmers growing relatively low value staple crops. This literature review summarizes research on the challenges and innovations in linking smallholder producers of staple grains to markets in Sub-Saharan Africa, with a focus on post-harvest issues including storage, aggregation, and transportation. For each post-harvest stage, we describe challenges faced by farmers and current efforts to address these challenges. In our review, we find a large amount of literature on the constraints to smallholder production and marketing but relatively few examples of innovative or novel technologies designed to improve storage and transportation for rural smallholder producers in Africa. Existing technologies have often been available for some time but have not seen widespread adoption, apparently due to high costs or inadequate funding for on-farm testing and extension. We conclude that the literature is somewhat divided as to whether interventions linking smallholder farmers to markets should be entirely market-driven and focus on linkages that can be profitable without subsidization, or whether NGO- and donor-driven interventions should play a role.

This report provides a general overview of trends in public and private agricultural research and development (R&D) funding and expenditures in Sub-Saharan Africa (SSA). The request is divided into two sections, covering public funding and private funding. Within each section, relevant data is presented on historical funding patterns, the types of research conducted, and which countries within SSA are financing R&D at the highest level. We find that the majority of growth in African public agricultural research funding took place in the 1960s, when real public spending on agricultural research increased 6% a year. From 1971 to 2000 annual growth averaged 1.4% a year. Public financing of agricultural R&D experienced a moderate shift in the 1990s from bilateral and multilateral donor funding to domestic government financing. The shift varied by country, but donor funding dropped for all SSA countries an average of 10%. Private research and development funding is heavily concentrated in developed countries with the United States and Japan the two biggest spenders. Within SSA, private R&D expenditures comprise 2% of all R&D spending. The main private actors in SSA are companies based in South Africa and Nigeria. The private sector is focused on research areas that involve marketable inputs, such as chemicals, seeds, and machines/

Special Economic Zones (SEZs) are generally defined as geographically delimited areas administered by a single body, offering certain incentives (duty-free importing and streamlined customs procedures, for instance) to businesses that physically locate within the zone. This literature review provides a baseline analysis of SEZs and their potential impacts on smallholder farmers in SSA. Criticism on SEZs is distinctly divided between those who criticize on social or environmental grounds versus those who question the economic impact of SEZs. SEZs are often criticized based on perceived negative socio-economic impacts—particularly their negative impact on women, labor, and working conditions. This review includes several country-specific studies that find evidence that SEZs actually have higher environmental standards and higher worker satisfaction than outside the SEZ. Most responses to criticisms do note, however, that the case studies’ results are not necessarily generalizable to SEZs throughout the world. The literature review includes key elements of successes and failures pulled from the case studies of SEZs in SSA. Though the evidence is insufficient to conclusively determine if smallholder farmers receive direct benefits from SEZs and their associated agroindustrial contracts, this review finds that resources provided to farmers (credit at rates lower than bank rates, technical or managerial assistance, pesticides, seeds, and fertilizer on credit) tend to be concentrated among larger farmers. The report concludes with a note on donor involvement as well as recommendations for further research.